Stadia instrument



Sept. 8, 1936. A. LANGSNER `STADIA INSTRUMENT s vsheets-shew 1 Filed May 14, 1954 Iliw Illllllllllllllllllllllll lllllll Illlllllllllll Sept. 8, 1936. A. LANGsNER STADIA INSTRUMENT Filed May 14, 1934 3 Sheets-Sheet 2 Jf/a y Sept. 8, 1936. A. LANGsNl-:R

-STADIA INSTRUMENT Filed May 14, 1934 3 ShebS-Sheet 3 Patented Sept. 8, 1936 UNITED STATES PATENT OFFICE STADIA INSTRUMENT Adolph Langsner, Chicago, Ill., assignor to Eugene Dietzgen Company, Chicago, Ill., a corporation of Delaware Application May 14, 1934, Serial No. 725,494

20 Claims. (Cl. 33-71) My invention relates in general to stadia in- Another important object is to arrange, in a struments and has more particular reference to stadia instrument having an angularity scale, the provision of means in a stadia instrument horizontal and vertical constant indicating scales for the direct determination of horizontal and in such position with respect to the angularity Vertical stadia constants. scale that the eye of an observer, reading the 5 An important object of the invention is to scales, may travel a continuous path whereby provide a stadia instrument having a, plurality rapid observation of the several scales is faciliof scales, including scales of variable stadia contated; a further object being to arrange the anstants, arranged relatively in readily observable gularity and constant scales in vertically superposition in the instrument, whereby observation posed relationship so that the observers eye may 10 of the several scales is facilitated. travel a straight vertical path from one to the Another important object is to provide a stadia Other t0 thus facilitate Observations. instrument having a plurality of scales and co- Another imperiant Object iS t0 PIOVde means Operating index means wherein the Scales are applicable to standard stadia instruments wherearranged in adjacent position in the instrument by the Same may be provided With horizontal 15 so that all may be observed at a, glance, a, furand Vertical constant determining Scales, in adther object being to arrange the scales so that dition to the ordinary angularity Scale forming the index marks are in alignment. a part of such instruments, without unduly in- Another important object is to provide a stadia creasing the 00st 0f instruments provided With instrument having adjacently arranged scales the additional constant determining scales. 2O of variable horizontal and vertioa1 constants and Numerous other objects and advantages of the common index means for said scales, invention will be apparent from the following Another object is to provide a stadia instrudescription, which, taken in connection with the ment having adjacently arranged scales of variaccompanying drawings, discloses preferred emable horizontal and vertical constants and aligned bodiments of my invention. 25

index means for said scales. Referring to the drawings:

Another object is to provide a stadia instru- Figure 1 is a. side elevation of an instrument ment having scales of variable horizontal and embodying my present invention; vertical stadia constants and co-operating index Figure 2 is an enlarged view of a portion of the means, the scales being in parallel adjacent ardevice illustrated in Figure 1; 30 rangement and the index means of the several Figure 3 is a sectional view taken substantially scales being on a common hue whereby to peralong the line 3--3 in Figure 2; mit the reading of the several scales substantial- Figure4 is a view of a stadia circle forming a ly simultaneously. part of the apparatus shown in Figure 1 and illus- Another important object is to arrange scales trating the several scales embodied in the instru- 35 of vertical and horizontal stadia constants, in a ment; stadia instrument, in vertically superposed rela- Figure 5 is a fragmentary view illustrating a tionship in the instrument in order to facilimodified arrangement of the transit; tate the reading of the same. Figure 6 is a sectional view taken substantially Another important object is to provide a stadia along the line 6--6 in Figure 5; 4 instrument having an angularity scale and scales Figure 'I is a view similar to that shown in of variable horizontal and vertical constants, Figure and illustrating another modied arwnd index means for said scales wherein the rangement of the device; index means of at least one and preferably of Figure 8 is a sectional View taken along the both of the constant scales is aligned with the line 8--8 in Figure '7; 45 index means of the angularity scale. Figure 9 is a fragmentary view of a modified Another object is to arrange a stadia instruform of the device illustrated in Figure 1;

ment having an angularity scale movable on a Figure 10 is a sectional Aview taken substanstandard and enclosed in a guard with a scale tially along the line IU-IU in Figure 9;

and horizontal constants movable with the anstill further modiiied arrangement of the device; gularity scale and having index means for one Figure 12 is a sectional view taken substanof the constant scales on the standard and intially along the line I2I2 in Figure 11; and

dex means for the other constant scales on the Figures 13, 14, and 15 illustrate a stadia circle guard. and associated scale segments utilized in the pro- 55 index on the standard and scales of vertical Figure 11 is a fragmentary view illustrating a 50 standar-ds 23 preferably in the form of A mem-A bers, at least one of which supports a frame portion forming a guard 39. rihe standards 23 are carried by the support 2l and in turn carry therebetween pivot means 25 journaled at its opposite ends in bearings 2': provided in the standards. The pivot means 25, in turn,.carries 'a telef scope 23, which is or may be provided with the usual stadia marks therein. The pivotl 'means enables the telescope to be tilted to a desired angle as is well known in the artof surveying and since the telescopeforms no part of the present invention, it is not thought necessary or desirable to describe the same in greater detail.

The pivot means, on one side of the telescope, carries a wheel 3! having an annular rim 33 and radial spokes 3J.. The wheelv has a hub 3:7, by which it is secured for rotation with the pivot means on one side of the telescope adjacent the standardv 23, which is provided with the guard 33 in position to encircle the wheel 3 I, said guard comprising a. rim iii, within which the rim 33 of the wheel is a-dapted to rotate. The guard also has radial spokes 43 extending between the rim and centrally located means forming a seat 0.5 whereby the guard may be mounted upon the upper end of theA A frame. The A frame is pro vided with fastening devices ill' and @9, by which the guard is secured to the frame on which it is mounted. Y Y

' The side'of-the rim 33, facing the A frame, on which the guard-is mounted, is formed with a scale-carrying'surface 5l and the outer periph- Y eral edge of this surfaceis provided with an angularity scale 53. The wheel 3l is positioned that when'the telescope 29 is tilted, the scaleprovided edge 53 will sweep across,` a Vernier scale 55 formed on the forwardly facing surface of a scale plate 5l, which is .mounted between the spaced' legs cfr-the A frame 23 as by suitably threaded fastening members 5S so that through the co-operation of the scales 53 and 55, theV tilted angularity of the telescope may be determined ata glance.

I have also provided co-operating means formedrin the guard or the frame 23 or both and on the Wheel'l by which vertical and horizontal stadiaA distance vconstants can be determined readily as a direct reading on the instrument after the same has 'been sighted and adjusted, In this connection, it should be understood that the telescope 29, as a part of its construction, is provided with rhorizontal cross-wires or hair lines so that when the observer sights the telescope upon a rod, the distance'. apparently subtended by the upper and lower'` hair lines may beread upon the rod. The distance sodetermined on the rod multiplied by a constant representing the spacement of theV upperand lower hair lines in the telescope, gives the distance between the instrument and the rod, providing, of course, that the telescope is horizontal.` If, however, it is necessary to incline the telescope tosight it upon the rod, it will be obvious that the apparent distance subtended on the rod between the upper and lower hair lines, multiplied by the constant previously referred to, will not give the true horizontal distance between the instrument and the rod. In order to determine the horizontal distance, it is necessary to make use of a trigonometrical formula involving the stadia distance and the cosine of the angle to which the telescope is tilted in sighting upon the rod. It is also possible to utilize a similar formula involving the stadia distance and the sine of the angle in order to determine the difference in elevation between the rod and the transit. These formulae may be arranged respectively as a vertical scale 59, and a horizontal scale 6l movable with the wheel 3l and having co-operating stationary marks arranged on the frame or guard to indicate on said scales the correct factor by which the stadia distance must be multiplied in order to givethe true vertical and horizontal distances between the instrument and the rod. To this end, l form the vertical and horizontal scales on the inner peripheral edge of the scale surface 5|, the horizontal and vertical scales being arranged in diametrically opposite relationship on the wheel rim 33 and one of said scales, preferably the vertical, being arranged in the surface 5l opposite the zero graduation of the angularity scale 53. An index mark G3 for the vertical scale so arranged is provided on an index plate 65, which is or may be mounted between the legs of the A frame 23 in any suitable fashion as by means of the threaded fastening members Sl. An index niark 33, preferably formed on a plate l! is provided for the horizontal scale. The plate 7| is preferably supported on the guard 39, the opposite ends of the plate ll being fastened to the upwardly extending arms 43 of the guard as by means of the threaded fastening members '3. The index plater 'li is thus ,carried by and between the arms i3 with the index mark S9 in position to indicate a graduation of the horizontal scale 6I. It will be noted that the vertical and horizontal scales 55 and 6! and their associated index marks 63 and 39 are in vertically superposed relationship with respect to each other and also with respect to the angularity scale 53. After the telescope has been cited upon the rod, the indicated reading on the several scales 53, 53, and El may be determined at a glance, it being necessary simply that the eye of the observer travel vertically upwardly along the center line of the guard, it being unnecessary even to change position in reading the several scales, thus the operation of the device is facilitated so readings may be accomplished more quickly and with less effort to the end that the utility of the device is greatly increased.

It will be noted also that the vertical and horizontal scales 5S and Si and their co-operating indices 63 and S3 are provided in the transit without materially altering the structure of the same, it being merely necessary to provide the scales 59 and 6I on the inner edge of a standard wheel and apply the index plates 65 and 7| respectively to the frame 23 and the guard 39, which may be accomplished by merely drilling the upwardly extending arms 53 to receive the fastening members 'T3 and without otherwise altering or providing a special guard. It is also a simple matter to attach the index plate B5 between the spaced legs of the frame 23. It is not even necessary to inscribe the scales 59 and GI upon the surface 5 I, but the same may be formed upon plates "i5 and l1 adapted for attachment between the adjacent legs 35 of the wheel 3| near its rim 33 as indicated in Figure 4, the plates l5 and VI being attached in any suitable fashion as by fastening members 19 threaded into perforations formed in the legs 35. The index marks 63 and 69 are formed in any suitable fashion as on plates similar to the plates 65 and 1 I, which are mounted between the legs of the frame 23 and the arms 45 of the guard in position to register with the scales 59 and 6|. Alternately, the index 63 and index 69 in the embodiments shown in Figures 1 through 4 may take the form illustrated in Figures through 8, in which the indices are ar ranged in the form of projections in a window plate carried by the frame 23 and the guard 39 `in position to overlie the scales 6| and 63 and expose the same through the window of the plate. The indices 63 and 69 also, if desired, may be arranged, as shown in Figures 9 through 12, in the form of hair lines on a plate of translucent material, such as glass, which is fitted into the frame 23 or the guard 39 in position to overlie the scales 59 and 6| and form a window through which the same are visible with the hair lines overlying said scales.

In Figures 5 and 6, I have illustrated an arrangement in which the vertical and horizontal scales 59 and 6| are both arranged in position Visible at the top of the wheel in diametrically opposite relationship with respect to the angularity scales 53 and 55, since it may, in some cases, be more convenient to have the vertical and horizontal scales close together instead of on opposite sides of the wheel as in the forms shown in Figures 1 through 4.

In the embodiment shown in Figures 5 and 6, the horizontal scale 6| is 'inscribed upon the inner edge of the scale surface 5| in a diametrically opposite relationship with respect to the normal zero mark of the scale 53. 'I'he vertical scale 59, however, is inscribed upon a sectional plate 8 l, which may be similar in form to the plate 15 of the embodiment illustrated in Figure 4 and.

which is attached between the arms 35 of the wheel 3| adjacent the inner edge of the scale surface 5|, on which the horizontal scale 6| is inscribed, the segmental plate 8| being secured in position in a manner similar to that employed in securing the segmental plate 11 in position in the arrangement shown in Figure 4. I also prefer to utilize a window plate 83 having an operture 85 and secured between the adjacent upwardly extending arms 43 of the guard 39 in order to frame and attract attention to the vertical and horizontal scales 59 and 6|, the window plate 83 may be formed as a sheet metal stamping if desired and is secured in place by suitable fastening devices 81 so as to expose the scales 59 and 6| in the opening 85. I'he upper and lower edges of the plate, defining the opening 85, are also preferably formed with projections 89 in position to register with the graduations of the scales 59 and 6| and these projections form the indices 63 and 69. If desired, the projections 89 may be omitted and the plate 83 iitted with a sheet ofV transparent material, such as glass, on which hair lines may be formed in position overlying the scales for the purpose of affording the index marks 63 and 69.

In Figures 7 and 8, I have illustrated an arrangement in which the vertical and horizontal scales 59 and 6| are arranged in position to be viewed on the lower side of the wheel 3| adjacent the angularity scales 53 and 55, since this arrangement permits of three scales to be viewed with the least possible effort. To this end, Ivinscribe the vertical scale 59 on .the inner edge of the scale surface 5| with its zero mark in registration with the zero graduation of the scale 53, while the horizontal scale 6| is formed upon a segmental plate 9|, which is secured between adjacent legs 35 of the'wheel in position such that the horizontal scale 6| registers with the vertical scale 59. The segmental plate 9| may be similar in form to the plate 11 of the embodiment illustrated in Figure 4 and may be secured in position in a manner similar to that employed in securing the plate 15 between the spokes of the wheel in said embodiment. A window plate 93, similar to the plate 83 and having an aperture 95, is provided in position to frame the scales 59 and 6| in said aperture, is mounted between the legs of the A frame in position to overlie the scales, the plate being held in position by the threaded fastening devices 61. The upper and lower edges, defining the aperture 95, may also be provided with projections 91 in position to deiine the indices 63 and 69, or the plate 93 may be provided with a glass window inscribed with hair lines forming the indices in a manner similar to that described in the embodiment shown in Figure 5.

It will be noted that the forms shown in Figures 5 and 7 may be fabricated by adding to standard transit parts, the segmental plates 8| or 9| as the case may be and by providing the window plates 83 or 93 and by inscribing the scale 6| or 59 in proper position upon the scale surface 5|. Consequently, a transit having vertical and horizontal scales may be provided at minimum expense.

In Figures 9 through 15, I have disclosed the possibility of providing vertical and horizontal scales in a standard transit without the necessity of inscribing these additional scales upon the scale surface 5| of the transit wheel. I may arrange the vertical and horizontal scales either at the top or at the bottom of the transit wheel. Where the scales are applied at the top of the wheel, I provide a segmental plate 99 having vertical and horizontal scales 59 and 6| inscribed on its opposite curved edges. This plate is mounted between the upwardly extending arms 35 of the transit wheel 3| preferably in a lmanner similar to that .employed in mounting the plate 11 in Figure 4 and the plate 8| in Figure 5. The plate is thus mounted on the wheel in diametrically opposite relationship with respect to the zero graduation of the angular scale 53. This arrangement is illustrated in Figures 9 and 10 of the drawings. If desired, a guard 39 may be used, the guard being provided with a window plate similar to the plate 83 of the embodiment shown in Figure 5.rv However, I prefer to provide a special guard 0| formed with a cross piece |03 between the upwardly extending legs 43 of the guard so that the space, between the crosspiece |03 and the edge |05 of the guard rim between the legs 43, defines a window |01 framing the scales 59 and 6| carried on the segmental plate 99. The guard also may be provided with a preferably glass plate |09 secured in the opening |01 in any suitable fashion as by means of cement and the plate |09 is provided with a hair line ||3 in position overlying the scales 59 and 6| and adapted to provide index means 63 and 69.

Alternately, as shown in Figures l1 and 12, vertical and horizontal scales 59 and 6| may be formed on opposite edges of a segmental plate adapted to be mounted on the lower side of the transit wheel in registration with the angularity Scale 53,;t'ne plate Habeingmoueted ,in-fa; matiz ner similar to -tl1,at employedirr mounting, thev plates in Figure i andai in Figure 7,1 Witlfr this arrangement, a window plate, simlallftothe; plate Sgebown in Figure '7, maybe prOVdedbIit: I prefer te employ-a frameA Il? having apferably-gl Window Hcverlying the segmentat plate l'` -nd providedvwith a hair line l?! :adapted to provide the indexmeans 63V and- S92 Itis thought tliat the inve t Y1 andnumerousof its attendantv advantages libe: understood; fromv the foregoing ,description and it isi-obvious,v that numerous changes may be made-in the f, constructmn,V and arrangement i,Y the severa-l, parts withoutdepa tingY from the spiritor scope, of ,my inventi or sacrificing any ofV its attendant ad itages; the forms herein-described being preieri-ed embodiments iop-the purpose illustrating my invention, Y

describedv i my invention, what 4I y, i. and desirerto secure bylletters Patent is as 4follows-z Y 1.A In a stadiainstrument, the combination with a frame, a-telescope provided'with stadia.wiresi HQ ving thuN mounted for angular adjustment with re-.,

spect to the frame, a member movablewith said telescope and having an arcuateportiorr Carr-ying an angularity scale and angularityindex means supportedgby said frame in positiomto-im, dieate, on scid angularity scale, theangularpositio-,n ci' sai-f1 rele cope with respect-to the-frames oi-means forming an addt, nal; scale immovable-1A with said telescope and graduatedin terms-of stadia constants varying with the-angleU-of' inclination of said telescope, and index-means-for said additional scale stationarily supported by iframe in vertical alignment'withY respect to` angularity index means.

In a stadia instrument, the combination with a g -ravingv spaced-legs atelescepeg.A pro-vided i' i stadia wires and mounted fortangular at with repect'to the frame;

, move.. Jitn` said ieleseopeandcarrying an angu alley scale in position exposed between the legs ci said frame, and angular* yvindex means carried 4bysaid frame, for indicat-VV ing on thenertions of said angularity; scale ,ex-v Nd bet-wcm said legs, the angular positionos id Vtelescope with respect the Vframe, of means forming an additional scale negotiable with; said telescope in positionl exposedcvbetweenwthe legsV of said-frame and graduated in terms -ofstadia constants varying with the anglelfoifineline-f on of said telescope, and ind-ex means for ditional scale supported by, said frame in posi n to co-c-perate with a, portionpf; said additional scale exposed betweqn the -legsof` said frame.

3. In a stadiainstrument, thecombination with a frame, a telescope-provided with stadiawires and mounted for angular adjustment with; re-. spe-ct to the frame, a member movable With-:said telescope having an arcuate.portiorrcarrying an angularity scale, and angularity indexmeans supported oy said frame inposition toindicateg en said ksingularity scale, theangular position of. said telescope with respect `to the franca-bfA` means forming additional; scales, movable Withf said telescopefand graduated respectively l in.,Y terms of vertical and horizontal stadia. constants; varying with tne angler of inclination of said telescope, said scales being arranged in parallel adjacent relationship and alignedgindex means, for Vsaid additional scales, stationarily `supported by said frame. l, g

fil

asin: a stadia.; instrument; the: combination nes mimountedgfor` aneularfadiustmentwitn lSPst-.to-:the: fromm a; member movable with Said telescope andfhaving anfarcuate portion carryirxglan mentality scaleland angular-ity index means supportcdtbasaidframe in position to indicate onsaid angnlarityscale; tha angular positional said telescope-with respect to the frame, dr means. forming7 anl additional scale movable witntsaidatelescopefandsraduated in terms of Stamm-constantesvarying wlththe angle of inclination; isaidrtelesoope, and indexrmeans for said ad 'anal scale stationarily.y supported by Saidiframein-,aligmnent with respect to said angularity: index;- meana. wherein, said yadditional scalels 4folrnedaonxarlseparate segmental plate attache detesthe. anglllarty lscale-carrying member.

.5i-lnx ai stadiavl instrument, the combination With-.a 1 frame,` 'al teleeconaiprovided with stadia Wiresiandmoun-ted ferffangular adjustment with respect; to :their-ame; a.member-movable with said telescope and having an arcuate portionl carryinganangularity--scale and `angularity index means .supportedabp :said -iramcin position to indicate, ori-,said angularitylscale, the angular position offsaidtelesoopewith. respect to the frame, otsmeans elimina an .additional scale movable with said'telescopeandgraduated in. terms of it'adia ieenstan-.tsi` varying with the angle of inclination :of saidftelescope, and index means for said` additional-scale stationary supported by said frame in alignment with; respect to saidan-4 gularity-Jindexgmeana. whereinv said additional scalaisllcrmedfoma separate segmental plate attaohe'dttol the angularity. scale-carrying member adjaeentean edge-oi aits arcuate portion.

6.11m., a. stadiafinstrument, the combination witliaa fremd'. ahtelescope.. provided with stadia Wires andfmountedfornangular adjustment with respect tothe -frame;a-.member movable with said telescopelandl-having ant-arcuate portion carrying an-angularityfscale and angularity index means :supportedfby-said frame in position to indioatefon-said angularity scale, the angular positioiroiisaid telescopemithrespect to the frame, of means-.forming an; additional scale` movable withz said teleseopeiand graduated in terms of -constants varyingwith the angle-oi inclinationi-offsaid telescope, and index means for saidadditional scale.; stationarily' supported vby said' frame ,in aligninentrivith-respect-'to said angularity.; indexe moana. wherein Said additional scaletisLfoiimedomas/separate segmental plate attaehedl 1to"=theiangularit'yscale-carrying Y member adjacentl the-'inner edgaof its arcuate portion.

'if In? a v stadia. instrument, the combination with a-irame, a-telescope provided with stadia Wires and mounted ionfangular adjustment with re sect 1to1 thewfrarne,l a member movable with saic telescope-and-having anjarcuate portion carrying an singularity scale. and angularity index means supported by said frame in'position to indicate, on saidangulari Ay scale, the angular' positiontofl said telescopewith respect to the frame, of means. forming any additional scale movable with said telescope and graduated in terms of stadi constantsI varying withl the angle of inclination-vof.-saidstelescope, andA index means for saidi'iadditional 'scalestationarily supported by said-:frame inzalignment with respect/to said aneulatityfndox; meansiwherein; the index means forfsaid additonalxsoaleiis formedon a separate index plate statianaartistA supported bythe frame.

with a frame, a telescope provided with stadia wires and mounted for angularadjustment with respect to the frame, a member movable'with said telescope and having an arcuate portion carrying an angularity scale and angularity index means supported by said frame in position to indicate, on said angularity scale, the angular position of said telescope with respect to the frame, of means forming an additional scale movable with said telescope and graduated in terms of stadia constants varying with the angle of inclination of said telescope, and index means for said additional scale stationarily supported by said frame in alignment with respect to said angularity index means, wherein the index means for said additional scale comprises an element having a Window and xed on the frame in position overlying said additional scale and exposing the same through said Window.

9. In a stadia instrument, the combination with a frame, a telescope provided with stadia wires and mounted for angular adjustment with respect to the frame, a member movable with said telescope and having an arcuate portion carrying an angularity scale and angularity index means supported by said frame in position to indicate, on said angularity scale, the angular position of said telescope with respect to the frame, of means forming an additional scale movable with said telescope and graduated in terms of stadia constants varyingwith the angle of inclination of saidtelescope, and index means for said additional scale stationarily supported by said frame in alignment with respect to said angularity index means, wherein the index means for said additional scale comprises a transparent plate having an index mark thereon and supported by the frame in position overlying said additional scales.

10. In a stadia instrument, the combination with a frame, a telescope provided with stadia wires and mounted for angular adjustment with respect to the Trame, a member movable with said telescope and having an arcuate portion carrying an angularity scaleand angularityv index means supported by said frame in position to indicate, on said angularity scale, the angular position of said telescope with respect to the frame, of means forming an additional scale movable with said telescope and graduated in terms of stadia constants varying with the angle of inclination of said telescope, and index means for said additional scale stationarily supported by said frame in alignment with respect to said angularity index means, wherein the angularity scale is formed in the outer edge and the additional scale is formed on the inner edge of said arcuate portion with its neutral graduation in alignment with the Zero graduation of the angularity scale.

11. In a stadia instrument, the combination with a frame, a telescope provided with stadia Wires and mounted for angular adjustment with respect to the frame, a member movablev with said telescope and having an arcuate portion carrying an angularity scale and angularity index means supported by said frame in position -to indicate, on said'angularity scale, the angular position of saidV telescope with respect to the frame, of means forming an additional scale movable with said telescope and graduated in terms of stadia constants varying with the angle of inclination of said telescope, and index means for said additional scale stationarily supported by said frame in alignment with respect to said angularity index means, wherein the angularity scale and the additional scale are formed in opposed edges of said arcuate portion and the index means for the scales are carried on separate members stationarily mounted on the frame on opposite sides of said arcuate scale-carrying portion.

12. In a stadia instrument, the combination with a frame, a telescope provided with stadia wires and mounted for angular adjustment with respect to the frame, a member movable with said telescope and having an arcuate portion carrying an angularity scale and angularity index means supported by said frame in position to indicate, on said angularity scale, the angular position of said telescope with respect to the frame, of means forming an additional scale movable with said telescope and graduated in terms of stadia constants varying with the Vangle of inclination of said telescope, and index means for' said additional scale stationarily supported by said frame in alignment with respect to said angularity index means, wherein the arcuate portion of the member comprises an annular surface with the angularity scale formed o n one circular edge of said surface and the additional scale formed on the opposite circular edge of said surface, the

neutral graduation of the additional scale being located in'diametral opposition on said annular surface with respect to the zero graduation of the angularity scale;

13. In a stadia instrument, the combination with a frame, a telescope provided with stadia wires andmounted for angular adjustmentwith respect to the frame, a member movable with said telescope and having an arcuate portion carrying an' angularity scale, and angularity index means supported by said frame in position to indicate, onsaid angularity scale, the angular position of said telescope with respect to the frame,

of means forming additional scales, movable with said telescope and graduated respectively in terms of vertical and horizontal stadia constants varying with the angle of inclination of said telescope, said scales being arranged in parallel adjacent relationship and aligned index means, for said additional scales, stationarily supported by said frame, wherein said additional scales are formed on a separate segmental plate-attached Yto the angularity scale-carryingmember.

14. In a stadia instrument, the combination with a frame, a telescope providedwith stadia wires and mounted for angular adjustment with respect to theA frame,A a member lmovable with said telescope and having an arcuate portion carrying an angularity scale, and angularity index means supported by said frame' in positionl to indicate, onA said angularity scale, the Aangular position of said telescope with respect to the frame, of means forming additional scales, movable With said telescope and graduated respectivelyin terms of vertical, and horizontal stadia constants varying with the' angle of inclination of said telescope, said-scales being arranged in parallel adjacent relationship and aligned index means, for said additional scales, stationarily supported-by said frame, wherein the angularity scale-andone of said additional scales are formedin opposed edges of said arcuate portion while another of said ad'- ditional scales is formed on ra separatesegmental plate attached to the angularity scale-carrying member.

15. In a stadia instrument, the combination with a frame, a telescope provided with stadia wires and mounted for angular adjustment with respect to the frame, a member movable with said telescope and having an arcuate portion carrying an angularity scale, and angularity index means supported by said frame in position to indicate, on said angularity scale, the angular position of said telescope with respect to the frame, of means forming additional scales, movable with said telescope and graduated respectively in terms of vertical and horizontal stadia constants varying with the angle of inclination of said telescope, said scales being arranged in parallel adjacent relationship and aligned index means, for said additional scales, stationarily supported by said frame, wherein the Varcuate portion of the member comprises an annular surface With the angularity scale formed thereon and wherein said additional scales are formed on a separate segmental plate attached to the angularity scalecarrying member with the neutral graduations of said additional scales lying in a plane including the zero graduation of the angularity scale and the axis about which said scale-carrying member is mounted for rotation in the frame.

16. In a stadia instrument, the combination with a frame, a telescope provided with stadia wires and mounted for angular adjustment with respect to the frame, a member movable with said telescope and having anl arcuate portion carrying an angularity scale and angularity index means supported by said frame in position centrally aligned vertically with respect to the axis of angular adjustment of the telescope, said angularity index cooperating in the angular scale to indicate the angular position of the telescope with respect to the frame, of members forming an additional scale movable with said telescope and graduated in terms of vertical stadia constants varying with the angle of inclination of the telescope, index means cooperatingly associated with said additional scale and stationarily supported by said frame in vertical alignment with respect to the axis of adjustment of the telescope, means forming another scale movable with said telescope and graduated in terms of horizontal stadia constants varying with the angle of inclination of said telescope and cooperating index means for said other scale and stationarily supported by said frame in vertical alignment with respect to the axis of adjustment of said telescope whereby the several index means are vertically aligned in said frame in order to facilitate reading of the several scales without changing the position of the observer.

17. In a stadia instrument, the combination with a frame, a telescope provided with stadia wires and. mounted for angular adjustment with respect to the trama. a member movable with said telescope and having an arcuate portion carrying an angularity scale, and angularity index means supported by said frame in position to indicate, on said angularity scale, the angular position of said telescopewith respect to the frame, of means forming additional scales, movable with said telescope and graduated respectively in terms of vertical and horizontal stadia constants varying with the angle of inclination of said telescope, said scales being arranged in parallel adjacent relationship and aligned index means, for said additional scales, stationarily supported by said frame, wherein said additional scales are formed on a separate segmental plate attached to the angularity scale carrying member adjacent the inner edge of its arcuate portion.

18. In a stadia instrument, the combination with a frame, a telescope provided with stadia Wires and mounted for angular adjustment With respect to the frame, a member movable with said telescope and having an arcuate portion carrying an angularity scale, and angularity index means supported by said frame in position to indicate, on said angularity scale, the angular position of said telescope with respect to the frame, of means forming additional scales, movable with said telescope and graduated respectively in terms of vertical and horizontal stadia constants' varying with the angle of inclination of said telescope, said scales being arranged in parallel adjacent relationship and aligned index means, for said additional scales, stationarily supported by said frame, wherein the angularity scale carrying member comprises an annular element and wherein the means forming the additional scales is arranged on said circle in position such that the neutral graduations of the additional scales are displaced angularly on the circle with respect to the neutral graduation of the angularity scale.

19. In a stadia instrument, the combination with a frame, a telescope provided with stadia wires and mounted for angular adjustment with respect to the frame, a member movable with said telescope and having an arcuate portion carrying an angularity scale, and angularity index means supported by said frame in position to indicate, on said angularity scale, the angular position of said telescope with respect to the frame, of means forming additional scales, movable with said telescope and graduated respectively in terms of vertical and horizontal stadia constants Varying with the angle of inclination of said telescope, said scales being arranged in parallel adjacent relationship and aligned index means, for said additional scales, stationarily supported by said. frame, wherein the index means for said additional scales is formed on a separate index plate stationarily supported by the frame.

20. In a stadia instrument, the combination with a frame, a telescope provided with stadia wires and mounted for angular adjustment with respect to the frame, a member movable With said telescope and having an arcuate portion carrying an angularity scale, and angularity index means supported by said frame in position to indicate, on said angularity scale, the angular position of said telescope with respect to the frame, of means forming additional scales, movable with said telescope and graduated respectively in terms of Vertical and horizontal stadia constants varying with the angle of inclination of said telescope, said scales being arranged in parallel adjacent relationship and aligned index means, for said additional scales, stationarily supported by said frame, wherein the index means for said additional scales comprises means xed on the frame and forming a Window in position overlying said additional scales and exposing the same in the window including index means in said window in position to cooperate with said additional scales.

ADOLPH LANGSNER. 

